We shall continue exploring the host and parasite factors relevant to the pathogenesis of schistosomiasis and of granuloma formation, with special emphasis on: Granuloma immunopotentiation by polysaccharide adjuvants; Liver cell damage and altered granuloma formation in mice with deficient T-cell lymphocyte function, and the ameliorating effect on these features of serum transfer from immunocompetent schistosome-infected mice; differences in the mechanisms of granuloma formation between Schistosoma mansoni and S. japonicum as they express themselves in both normal and in T-cell deficient hosts; analysis of the T-cell subsets involved in modulation of S. mansoni granulomas in vivo, which are being carried out by a collaborating group of investigators; the immunopathogenesis and fine structure of the Hoeppli phenomenon as observed in S. japonicum and S. mekongi infected hosts; the formation of the schistosome eggshell in the vitellaria of the female worm, and its cytochemical aspects; as well as related studies derived from these current subprojects. Our aim is to better define the factors which modulate the cell populations and morphological features of schistosome egg granulomas, and to better understand the pathogenic consequences of defective, normal, and excessive host immunological reactivity against schistosome eggs.